A warm drink of milk before bed has long been the best choice for those wanting a good night's sleep. But now a study has found it really does help people nod off（打瞌睡）—if it is milked from a cow at night.

    Researchers have discovered that “night milk” contains more melatonin(褪黑激素), which has been proven to help people feel sleepy and reduce anxiety（焦虑）.The study, by researchers from Seoul, South Korea, involved mice being fed with dried milk powder（奶粉） made from cows milked both during the day and at night. Those given night milk, which contained 10 times the amount of melatonin, were less active and less anxious than those fed with the milk collected during daytime, according to the study published in The Journal of Medicinal Food.

    Night milk quickened the start of sleep and caused the mice to sleep longer.

    While the effect of cow milk harvested at different time has not been tested on humans up to now, taking melatonin drugs has been suggested to those who have trouble falling asleep at night.

    Previous （以前的）studies have also showed that milk can be excellent for helping sleep because of the calcium content, which helps people to relax.

    Every object tells a story. Even the most ordinary objects can present to us powerful images. Sometimes it is the ordinary nature of these objects that actually makes them so extraordinary. Such is the case with an old leather shoe in a museum in Alaska. At first glance it does not look like much. It is a woman's shoe of a style popular in the 1890s. But what is unique (独特的) about this shoe is where it was found. It was discovered on the Checkout Pass, the famous trail used by the people seeking gold in Alaska. Who it belonged to or why it was left there is not known. Was it perhaps dropped by accident as the woman climbed up the 1500 stairs carved outface? Or did she throw away goods that she didn't need in order to travel lighter?

    Over 100, 000 people with “gold fever” made this trip hoping to become millionaires. Few of them understood that on their way they would have to cross a harsh wildness. Unprepared for such a dangerous journey, many died of starvation and exposure to the cold weather.

    The Canadian government finally started requiring the gold seekers to bring one ton of supplies with them. This was thought to be enough for a person to survive for one year. They would carry their supplies in backpacks (背包) each weighing up to fifty pounds; it usually took at least 40 trips to get everything to the top and over the pass. Whoever dropped the shoe must have been a brave and determined woman. Perhaps she was successful and made it to Alaska. Perhaps she had to turn back in defeat. No one will ever know for sure, but what we do know is that she took part in one of the greatest adventures in the 19th century.

    Breakdancing is set to make its debut(首次亮相) as an Olympic sport at Paris2024, Tony Estanguet, head of the Paris organizing committee, said on February 21". Skateboarding, sport climbing and surfing which have already been added to the 2020 Tokyo Olympics, have been invited to return in Paris.

    Estanguet said the choices responded to a need to make the Olympics "more urban" and “more artistic". "We have chosen to present the International Olympic Committee (IOC) with the four sports because they are creative, appealing to youth and completely in line with our vision. They reflect perfectly Paris 2024's identity.”

    Breakdancing is an example of a sport "which can be played anywhere and anytime in urban and other environments." It appeared at the 2018 Youth Olympics in Buenos Aires in the form of head-to-head "battles". In competitive breakdancing, "breakers face off in "battles" against each other, either as individuals or teams. Breakdancers use- a mix of physical and artistic skills combining elements from gymnastics or acrobatics(杂技).

    The IOC had announced that the number of competitors at Paris 2024 would be restricted to 10,500, which limited the opportunity to add sports. But the organizers said the inclusion would not necessitate the construction of permanent facilities and would involve just 248 competitors, including 32 breakdancers. The surfing events are likely to be held in established surf center such as Biarritz or Lacanau in southwest France.

    The inclusion still needs to be rubberstamped by the IOC, which is expected to decide on which sports to add in Paris after next year's Tokyo Games.

    Newborns begin to develop language skills long before they begin speaking. And, compared to adults, they develop these skills more quickly. People have a hard time learning new languages as they grow older, but babies have the ability to learn any language easily.

    For a long time, scientists have tried to explain how such young children can learn the complicated (复杂的) grammatical rules and sounds of a language. Now, researchers are getting a better idea of what's happening in the brains of the tiniest language learners. This new information might help kids with learning problems as well as adults who want to learn new languages. It might even help scientists who are trying to design computers that can communicate like people do.

    Most babies go "ma ma" by 6 months of age, and most children speak in full sentences by age 3. For many years, scientists have wondered how the brains of young children figure out how to communicate using language. With help from new technologies, scientists are now finding that babies begin life with the ability to learn any language. They get into contact (接触) with other people, listen to what they say and watch their movements very closely. That is why they quickly master the languages they hear most often.

    Studies show that, up to about 6 months of age, babies can recognize all the sounds that make up all the languages in the world. Starting at around 6 months old a baby's brain focuses on the most common sounds it hears. Then, children begin responding only to the sounds of the language they hear the most.

    In a similar way older babies start recognizing the patterns that make up the rules of their native language. For example, English children who are about 18 months old start to figure out that words ending in "-ing" or "-ed" are usually verbs, and that verbs are action words.

    "You can use me as a last resort(选择), and if nobody else volunteers, then I will do it." This was an actual reply from a parent after I put out a request for volunteers for my kids' lacrosse(长曲棍球) club.

    I guess that there's probably some demanding work schedule, or social anxiety around stepping up to help for an unknown sport. She may just need a little persuading. So I try again and tug at the heartstrings. I mention the single parent with four kids running the show and I talk about the dad coaching a team that his kids aren't even on … At this point the unwilling parent speaks up, "Alright. Yes, I'll do it."

    I'm secretly relieved because I know there's real power in sharing volunteer responsibilities among many. The unwilling parent organizes the meal schedule, sends out emails, and collects money for end-of-season gifts. Somewhere along the way, the same parent ends up becoming an invaluable member of the team. The coach is able to focus on the kids while the other parents are relieved to be off the hook for another season. Handing out sliced oranges to bloodthirsty kids can be as exciting as watching your own kid score a goal.

    Still, most of us volunteers breathe a sigh of relief when the season comes to a close. That relief is coupled with a deep understanding of why the same people keep coming back for more: Connecting to the community(社区) as you freely give your time, money, skills, or services provides a real joy. Volunteering just feels so good.

    In that sense, I'm pretty sure volunteering is more of a selfish act than I'd freely like to admit. However, if others benefit in the process, and I get some reward too, does it really matter where my motivation lies?

    Still seeking a destination for your weekend break? There are some places which are probably a mere walk away from your college.

    King's Art Centre

    A day at the Centre could mean a visit to an exhibition of the work of one of the most interesting contemporary artists on show anywhere. This weekend sees the opening of an exhibition of four local artists.

    You could attend a class teaching you how to learn from the masters' or get more creative with paint—free of charge.

    The Centre also runs two life drawing classes for which there is a small fee.

    The Botanic Garden

    The Garden has over 8,000 plant species；it holds the research and teaching collection of living plants for Cambridge University.

    The multibranched Torch Aloe here is impressive. The African plant produces red flowers above bluegreen leaves, and is not one to miss.

    Get to the display house to see Dionaea muscipula a plant more commonly known as the Venus Flytrap that feeds on insects and other small animals.

    The Garden is also a place for wildlife enthusiasts. Look for grass snakes in the lake. A snake called ‘Hissing Sid' is regularly seen lying in the heat of the warm sun.

    Byron's Pool

    Many stories surround Lord Byron's time as a student of Cambridge University.  Arriving in 1805, he wrote a letter complaining that it was a place of "mess and drunkenness". However, it seems as though Byron did manage to pass the time pleasantly enough. I'm not just talking about the pet bear he kept in his rooms. He spent a great deal of time walking in the village.

    It is also said that on occasion Byron swam naked by moonlight in the lake, which is now known as Byron's Pool. A couple of miles past Grantchester in the south Cambridgeshire countryside, the pool is surrounded by beautiful circular paths around the fields. The cries of invisible birds make the trip a lovely experience and on the way home you can drop into the village for afternoon tea. If you don't trust me, then perhaps you'll take it from Virginia Woolf—over a century after Byron, she reportedly took a trip to swim in the same pool.